1. Field of the Invention
This invention is concerned with apparatus for collection of animal exhalation and extends to feed stalls and milking apparatus including such apparatus.
2. Description of the Related Art
In the field of animal husbandry there is a continuing requirement to improve the overall yields obtained from livestock. Examples of areas in which improved yields are considered to be desirable include milk and meat production. It is generally accepted that the best way of achieving production targets set is to ensure that the animals are in good health. For example, the health of a ruminant animal such as a cow is influenced by its metabolic state. Animals with metabolic deficiencies tend to give yields that are significantly lower than animals which are in good health. Examples of metabolic conditions which adversely affect yield include ketosis and mastitis in cows.
It has become good practice to monitor the health of individual animals in the herd so that any problems arising which may adversely affect yield can be detected and rectified at an early stage. Monitoring techniques employed include weighing and measuring the animals and collecting samples of blood, urine, saliva and semen. By using these techniques a skilled person is able to establish a health profile for each animal.
Although weighing and measuring an animal is non-intrusive, the collection of urine and particularly blood samples is intrinsically intrusive and requires significant manual effort. A requirement to have the samples collected and analysed remotely together with the inevitable delay before receipt of the results and therefore diagnosis represents a significant disadvantage as any adverse condition of the animal may have deteriorated unnecessarily. The collection of blood and urine samples is, therefore, generally inconvenient and is only considered to be feasible on an intermittent rather than a regular basis and thus it is not possible to monitor the animal on a day to day basis using these techniques.
Methods for monitoring animal derived exhalations, particularly their exhaled breath, provide non-intrusive techniques which give useful information about health status. Preferably exhalation derived from the lungs is collected and especially the end tidal portion thereof as this contains components, some of them volatile, which have passed from the blood vessels into the alveoli. It can therefore be appreciated that it is possible by monitoring exhalation derived from the lungs to estimate certain volatile components of blood.
Apparatus and methods for the collection of non-human animal derived exhalation are disclosed in WO 94/12019 and WO 94/12022.
Apparatus for the collection and monitoring of human exhalation samples are well known and have been described in U.S. Pat. No. 4,202,352 and EP 0 650 051. U.S. Pat. No. 4,202,352 discloses apparatus which provide a solution to the problem of how to collect a series of rapid and shallow breaths from an infant. EP 0 650 051 discloses apparatus for the collection of human exhalation which includes a mouthpiece into which a patient is required to exhale deeply in response to instructions given by an operator. In both U.S. Pat. No. 4,202,352 and EP 0 650 051 the patients can be considered to be compliant. By compliant it is to be understood that the patient is cooperative. Adult humans in particular are able to understand any instructions given and/or are not disturbed by the presence of the collection apparatus, while infants do not offer serious resistance. Collection of an exhalation sample from a non-human animal is prone to difficulties. A non-human animal can be considered to be a non-compliant patient; it is unable to follow instructions given to it regarding when and how to provide an exhalation sample and it is easily disturbed by a change in its surroundings. The problem of collecting exhalation from a non-human animal has been addressed in part by WO 97/00444 which provides apparatus suitable for the collection of non-human animal exhalation. The apparatus includes a flow sensor positioned at the inlet which detects the presence of animal exhalation and thereby controls when an exhalation sample is collected. A long, thin inlet tube adapted to be placed in the nostril of the animal for collection of the sample minimises any disturbance experienced.
However, before the apparatus according to WO 97/00444 is used to collect a sample, it is necessary to restrain the animal. This requires considerable manual effort and tends to disturb the animal whose breathing becomes extremely rapid and shallow as a result so that any exhalation sample collected is rendered less representative of blood content.
Collection of a sample using the apparatus of WO 97/00444 requires knowledge regarding the position of the animal's head. The problems associated with the collection of a sample using this apparatus mean that it is not possible to use it in an automated setting without modification. In addition use of the apparatus requires significant manual input which makes its use on a daily or routine basis expensive and time consuming.
There is a need to be able to collect animal exhalation samples, automatically on a routine basis, e.g. daily. There is also a need to be able to collect exhalations closely corresponding in volatiles content to blood, e.g. such as those obtainable from an animal taking deep and regular breaths such as from a relaxed animal. Obtaining such exhalations is required without the uncertainty of whether or not the animals' head is in the correct position for sampling. The present invention addresses these needs.